Biting flies cause significant welfare compromise in horses through pain, blood loss, and behavioural disruption. Effective fly control is an important but often underestimated welfare priority.
The welfare impact of biting flies on horses is routinely underappreciated, as the constant harassment during fly season causes chronic stress, significantly reduces grazing time, and causes physical pain and irritation. Horses pestered by flies spend energy on avoidance that would otherwise support productive behaviour, and the associated stress responses have physiological welfare consequences. Fly prevention through physical barriers including fly rugs and masks, chemical repellents appropriately chosen for the species of flies present, and environmental management to reduce breeding sites provides meaningful welfare benefit at relatively low cost. Stabling during peak fly activity periods reduces exposure but introduces the welfare costs of confinement, requiring careful management to balance competing welfare priorities.